The first one, loi Évin oblige means “à cause de la loi Évin” ou “grâce à la loi Évin “, depending on whether you see the effect as negative (the former) or positive (the latter). This is equivalent to “because of” or “thanks to”.

Here, it is seen as negative because the loi Évin restricts the advertisement of alcohol and tobacco. (thanks to @Luke Sawczak for the information)

Secondly, victoire hexagonale means a victory by a French entrant. This is because France is commonly referred to as “l’hexagone” due to its shape. And “hexagonale” means hexagon-shaped, so in this case it means “a victory for France”.